Hedgehog signal pathway affecting myelin development and repair through cholesterol Deregulation

we used the active point mutant model RosaM2 to inject tamoxifen at specific postnatal time periods to induce Smo overexpression in brain OPCs. Meanwhile, we used lpc-induced acute demyelination as a pathological model to explore the effect of Smo on OL differentiation under pathological conditions. The cortex and CC of SmoM2-OE (RosaM2; pdgfra-creER) and littermates were then analyzed using rna-sequencing to explore the molecular mechanisms. Our results reveal that activing hedgehog signaling in opcs (1) affects ol proper differentiation and reduces myelination; and (2) alters cholesterol biosynthesis and trafficking in mouse oligodendrocytes. We have refined the regulatory network of oligodendrocyte development and myelination, established the functional link between the Hh signaling pathway, cholesterol homeostasis and myelination, and provided guidance for the application of Hh agonists/antagonists in the treatment of demyelination-related neurodegenerative diseases. Overall design: In view of our findings that overexpression of Smoothened(Smo) delays oligodendrocyte differentiation, we tried to identify downstream target genes regulated by Smo through RNA-sequencing. This analysis was collected the bulk RNA of cortex and corpus callosum from P15 SmoM2-OE mice and wild-type controls. We identified 2808 upregulated and 2474 downregulated genes (log2FC=1, p=0.05) in SmoM2-OE mice compared to control littermates. Please note that the data columns (in the Differentially_expressed_genes.csv) belong to the samples as below: sample title processed data column header CC+Cortex, P15, Mu, rep1 P15_2 CC+Cortex, P15, Mu, rep2 P15_7 CC+Cortex, P15, WT, rep1 P15_1 CC+Cortex, P15, WT, rep2 P15_3